求解空指针异常？？
package org.apache.jsp;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.jsp.*;
import java.sql.ResultSet;
import user.user_operation;
import java.sql.SQLException;

public final class checkLogin_jsp extends org.apache.jasper.runtime.HttpJspBase
  implements org.apache.jasper.runtime.JspSourceDependent {

  private static final JspFactory _jspxFactory = JspFactory.getDefaultFactory();

  private static java.util.List _jspx_dependants;

  private javax.el.ExpressionFactory _el_expressionfactory;
  private org.apache.AnnotationProcessor _jsp_annotationprocessor;

  public Object getDependants() {
  return _jspx_dependants;
  }

  public void _jspInit() {
  _el_expressionfactory = _jspxFactory.getJspApplicationContext(getServletConfig().getServletContext()).getExpressionFactory();
  _jsp_annotationprocessor = (org.apache.AnnotationProcessor) getServletConfig().getServletContext().getAttribute(org.apache.AnnotationProcessor.class.getName());
  }

  public void _jspDestroy() {
  }

  public void _jspService(HttpServletRequest request, HttpServletResponse response)
  throws java.io.IOException, ServletException {

  PageContext pageContext = null;
  HttpSession session = null;
  ServletContext application = null;
  ServletConfig config = null;
  JspWriter out = null;
  Object page = this;
  JspWriter _jspx_out = null;
  PageContext _jspx_page_context = null;


  try {
  response.setContentType("text/html;charset=GB2312");
  pageContext = _jspxFactory.getPageContext(this, request, response,
  null, true, 8192, true);
  _jspx_page_context = pageContext;
  application = pageContext.getServletContext();
  config = pageContext.getServletConfig();
  session = pageContext.getSession();
  out = pageContext.getOut();
  _jspx_out = out;

  out.write("\r\n");
  out.write("\r\n");
//-------接收输入参数------------
  int sysuser_role=0;
  ResultSet rs=null;
try{
  sysuser_role=Integer.parseInt(request.getParameter("sysuser_role"));
  }catch(Exception e){}
  String sysuser_password=request.getParameter("sysuser_password");
  String sysuser_name=request.getParameter("sysuser_name");
  String certCode=request.getParameter("certCode");
  //------查询数据库------
user_operation uop=new user_operation();
rs=uop.getUserOne(sysuser_name,sysuser_password,sysuser_role);
int rowCount=0;
try{
rs.next();
rowCount=1;
}catch(SQLException e){} if(rowCount!=0&&certCode.equals((String)session.getAttribute("certCode"))){
//------通过检查------
session.setAttribute("sysuser_id",rs.getString("sysuser_id"));
response.sendRedirect("./index.jsp");
}else{
response.sendRedirect("./login.jsp");
}

  out.write('\r');
  out.write('\n');
  } catch (Throwable t) {
  if (!(t instanceof SkipPageException)){
  out = _jspx_out;
  if (out != null && out.getBufferSize() != 0)
  try { out.clearBuffer(); } catch (java.io.IOException e) {}
  if (_jspx_page_context != null) _jspx_page_context.handlePageException(t);
  }
  } finally {
  _jspxFactory.releasePageContext(_jspx_page_context);
  }